Tex. Water Code § 26.3511

(a) Notwithstanding Section 26.351(c) of this code, to the extent that the commission pays from the petroleum storage tank remediation account or from sources other than the waste management account the expenses of the investigations, cleanups, and corrective action measures it performs, the commission may undertake those corrective action measures described in Section 26.351 of this code in response to a release or a threatened release from an underground or aboveground storage tank under any circumstances in which the commission considers it necessary to protect the public health and safety or the environment.

(b) The state, the commission, and their agents or employees are not liable for damages arising out of the loss of access to or the use of real property or losses to a business located on the real property if those damages arise out of a delay in procuring services for corrective action, initiating corrective action, or completing corrective action on the property. This subsection applies only to cases in which the commission undertakes corrective action.